The diversity and abundance of fish species in Ekpene Ukpa River were studied from July - October, 2020. Sampling was by direct observation of the fish species at the sampling sites following landing by fishermen. Frequency, counts, and percentages were employed to determine fish species composition and abundance, while a Microsoft Excel 2003 based program was used to determine the ecological indices. A total of 14 species belonging to seven (7) families were recorded. The family, Clarotidae had the highest relative abundance (38.1%) with the least value (2.38%) observed in the family Alestidae. The index of preponderance ranged from 0.0004 in Pellonula leonensis and Trachinotus teraria to 0.100 in Chrysichthys nigrodigitatus. The most abundant grouping of fish species was Chrysichthys igrodigitatus with 25.0% and the least in abundance were Pellonula leonensis and Trachinotus teraia with 1.19% each. The index of preponderance (IP) value of 0.10 was recorded for Chrysichthys nigrodigitatus which marked this species very significant in the study site. The study revealed that species richness and diversity were high in the month of October. Inference from the results clearly indicated that fish species were much diversified in all sampling months, and this is of great significance to the biodiversity of the study area. However, an inclusive management approach is recommended, such as educational awareness, involving of the local contents, and comprehensive rational planning on the management and development of the study site.